Jeffrey Pyne Trial: Jurors Hear 911 Tapes

The murder trial of a former high school valedictorian and college biology student accused of brutally murdering his mother began Friday as prosecutors played 911 tapes and showed photos of the blisters on his hands in the hours following the crime.

Jeffrey Pyne, 22, allegedly murdered his mentally ill mother, Ruth Pyne, 51, in May 2011 by bludgeoning and stabbing 16 times in the family garage in Highland Township, Mich.

She was bipolar and had spent two weeks in jail nine months before her death for attempting to strangle Jeffrey.

"He hit her in the back of the head and hit her again, and again and again and again," the prosecutor said.

Ruth's husband Bernard and 11-year-old daughter found her body. The 911 tapes played in court Friday demonstrated their horror and confusion at the discovery.

Jeffrey Pyne sat expressionless through the opening statements. He was arrested five months after the murder and held without bond for more than a year. Because he was indicted by a secret grand jury, little was known about the evidence stacked against him.

Prosecutors showed jurors photos of the blisters on Jeffrey's hands hours after the murder. He explained the wounds to his boss as the results of throwing a shipping pallet.

"It did seem odd to me," his boss, farmer William Cartwright said. "I expected more of a splinter or scrape than what looked like rope burns."

Still, community members and Jeffrey's father Bernard maintain that he is innocent. It took two days to find an impartial, 12-member jury.

"The people in the community are hugely supportive of this young man," Detroit Free Press journalist Lori Brasier told ABC News. "Even people who believe he may have actually killed his mother still support him, and you don't usually find that in the community."

Jeffrey Pyne's defense attorneys say he is innocent, too.

"Somebody else committed the crime," they said. "We believe the evidence will show you that."

The trial is expected to last for two or three weeks. If convicted, Jeffrey Pyne faces life in prison.

"This is going to be a tough case for prosecutors," said Dan Abrams, legal analyst for ABC News. "Not only is the physical evidence limited, but you've got a really sympathetic defendant."